<!DOCTYPE html>
<html>
<head>
	<meta charset="UTF-8">
	<title>双项目</title>
</head>
<style type="text/css" media="screen">
.box{
	display: flex;
    height: 100vh;
    flex-direction: column;
	justify-content: space-between;
	align-items: center;
	
}
.item{
	width: 50px;
	height: 50px;
	line-height: 50px;
	text-align: center;
	
	background-color: red;
}	
</style>
<body>
<div class="box">
	<span class="item">
		你好
	</span>
	<span class="item">
		你好
	</span
</div>
</body>
</html>